Amidst the current ingredients debate on all things drying, much of the world's hair media seem to have missed a spot: salt.

How can something so small have such a big impact on your hair – and how does it get into your tresses in the first place. . .

The trouble with salt. . .

Sodium chloride, or regular table salt, is a surprisingly common ingredient in shampoo formulations. Manufacturers use it as a cheap way to thicken a shampoo, giving an illusory, luxurious feel. While the public attention has recently become fixated on sulfates, a more important clue as to whether a shampoo will dry out your hair or not is whether it contains salt.

Salt in a shampoo has the same effect that salt in sea water has on your hair; it is powerfully drying. So powerful, that it does not need to be present in large volumes to do damage.

The same crystals of sodium and chlorine that are vital in minute amounts for the functioning of our cells, and the tastefulness of our food, can also desiccate your hair at remarkably low concentrations.

The average concentration of salt in sea water is just 3.5%, yet you probably know from experience that just a few dips is enough to seriously dehydrate your hair. In shampoos the amount is lower – usually, formulators simply add it in tiny increments until enough has been added to arrived at the desired thickness. Still, in shampoos salt is present in conjunction with cleansers which, by their very nature, are designed to strip away oily debris from your hair. The combination can be extremely unforgiving on your hair.

In haircare capital the Dominican Republic, hair moisture is seen as a vital resource. With the rays of the Caribbean sun to contend with, and a rigorous national beauty regimen, closely guarding hair hydration is always a must.

No surprise then, that a number of years ago, following reports from women of a drying effect on their hair from products which contained the ingredient, there was an outcry by beauticians and lay hair connoisseurs alike, leading to an anti-salt awareness among the public.

In turn, many manufacturers hurried to pin “no contiene sal” or “salt-free”, on their labels in order to distinguish their products from cheaper lines on the market which used salt to bulk out unappealingly watery formulations. While the salt kicked up the thickness of the product, that was no exchange for the precious moisture it was pulling from the hair.

In the UK, however, the salt factor is not so well-known, and many widely-used shampoos on the market do contain this drying ingredient. In the chatter both online and offline about ingredients, it's often missed. Considering the impact it can have on your tresses, it really ought not to be.

Ingredient hysteria?It's certainly true that current trends around ingredient scares are, at best, oversimplified and at worst, bordering on the hysterical. After all, really knowing how to read an ingredients list is not as simple as “good” ingredient = good for my hair, “bad” ingredient = bad for my hair.

However, salt content is one of the few cases where the presence of one ingredient can be enough to reject a whole product right off the bat.

One bad encounter with a salt-surfactant combo can be enough to dry your hair to breaking point. And in the worst cases, it can be nigh on impossible to bring things back to the full hundred.

While sulfates and other surfactants can be made gentler simply by decreasing their concentration in the product, salt has such a strong, inherent cleansing action, even used at low concentrations, that it is better to go for no-salt, rather than just low salt. With summer fast approaching, and long days at the beach beckoning for the lucky ones among us, your hair is likely to get more than enough salt at the seaside. To keep it happy and manageable, best not to saturate it it in the same at home.